31
MAINTENANCE SECTION
7.
Place the narrow end of the Clutch Return Spring (46
or 65) in the Rear Gear Case against the inner race of
the Spindle Bearing (44).
8. Place the hex drive end of the Clutch Input Driver (47
or 66) on the Spring and compress the Spring until
the hex on the Driver enters the hex recess in the
Spindle Assembly (42). While holding the Driver in
position, engage the raised bar on the face of the
Driver with the jaw of the Cam Jaw (54 or 70).
The following step has parts with a left–hand
thread. Rotate the components counterclockwise
to tighten them.
9.
Install the Clutch Housing (81) over the clutch
components and thread it onto the Rear Gear Case.
Using a 1–1/16” wrench on the flats of the Rear Gear
Case and the Clutch Housing Spanner Wrench (Part
No. TRH–478) in the clutch housing slot, tighten the
joint between 15 and 20 ft–lbs. (20 and 27 Nm)
torque.
10. Invert the assembled tool in the vise jaws and lightly
grasp the flats on the Rear Gear Case with the inlet
end of the tool upward.
11. Insert a 5/8” dowel through the opening in the Back
Cap (7), and using the dowel as an alignment device,
install the three Muffler Elements (9) in the cavity of
the Back Cap. Make certain the notches in the outer
edge of the Elements fit over the memory chip pocket
in the bottom of the Cap.
12. If the tool is equipped with a Memory Chip (10),
install it (with the leads entering first) in the pocket at
the bottom of the Back Cap.
13. Make certain the tab on the inside edge of the Back
Cap Gasket (8) is aligned with the pocket for the
Memory Chip and install the Gasket, metal face
leading, in the recess of the Back Cap against the face
with the cavity containing the Muffler Elements.
14. Position the gasket end of the alignment dowel
against the inlet hub on the Motor Housing. Align
the flats on the Cap with the flats on the Housing.
Orient the Back Cap and slide the Back Cap
Assembly off the alignment dowel and onto the
Motor Housing.
15. For all Models with a Shutoff Clutch, install the
Push Rod (35) into the central hole in the inlet hub.
The Rod will enter the assembled motor and
disappear from view when released. Install the
Shutoff Valve (21), small end first, in the same
opening.
16. Being careful not to damage it, insert the Throttle
Valve Seat (13) into the central opening at the inlet
end of the Motor Housing at an angle until it clears
the threads in the Housing. Using a rod with a flat
end and no sharp edges, push the Seat to the bottom
of the opening until it seats flush.
17. Using needle nose pliers, insert the Throttle Valve
(14), long stem leading, into the opening against the
Seat. Center the Valve in the Seat.
18. Install the Throttle Valve Spring (15) in the opening
so that it encircles the Valve.
19. The Exhaust Diffuser (16) has one slot that is longer
than the other five slots. The Back Cap has a short,
molded stud projecting from the inlet end. Place the
Exhaust Diffuser against the Back Cap with the long
slot encircling the molded stud. Rotate the Diffuser
counterclockwise until the wall of the slot stops
against the stud. The exhaust ports are now in the
full open position which will provide maximum free
speed.
20. If the Inlet Screen (19) required replacement, use a
wooden dowel to carefully push a new one into the
Inlet Bushing (17).
21. If the Inlet Bushing Seal (18) is nicked or damaged,
carefully install a new one over the threads of the
Inlet Bushing.
22. Thread the Inlet Bushing Assembly through the
Diffuser and Back Cap into the Motor Housing.
Using a 1–3/16” wrench on the flats of the Back Cap
to keep it from turning, tighten the Inlet Bushing
between 15 and 20 ft–lbs. (20 and 27 Nm) torque.
23. The Throttle Plunger (6) has a lengthwise flat on the
outer edge at one end of the Plunger. Insert the
Plunger, flat end first, into the cross hole in the
Housing. Push on the end of the Plunger to make
certain it springs back from contact with the stem of
the Throttle Valve.
24. Position the Throttle Lever (11) in the slot in the
Back Cap and Motor Housing and using a 1/16”
diameter rod, align the holes through the Back Cap,
Motor Housing and Throttle Lever. While
maintaining alignment, install the Throttle Lever Pin
(12) in place of the rod by tapping it through all three
pieces.
25. Remove the tool from the vise jaws and install the
Grip Assembly (95), internal slotted end leading, over
the Clutch Housing and Rear Gear Case. Engage the
slots in the Grip Assembly with the notches on the
Motor Housing (1).
